Observations on the topographical relations of spinal nerve roots in the rat

Padmanabhan, R.; Singh, Simranjeet

doi:10.1159/000145142

Cited by 22 publications

(13 citation statements)

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“…Six rats were set up for intrathecal application of capromorelin and to record both bladder and colon pressures and propulsion of colonic contents. Capromorelin (250 μg), injected into the subarachnoid space of the lumbar spinal cord at vertebral levels L1–L2, corresponding to spinal cord levels L4–S4, 18 caused an increase in the frequency and amplitude of colonic propulsive contractions and an increase in fluid propelled by the colon (Fig. 5), as reported previously 8 .…”

Section: Resultssupporting

confidence: 83%

Evidence for functional ghrelin receptors on parasympathetic preganglionic neurons of micturition control pathways in the rat

Ferens¹,

Yin²,

Ohashi-Doi³

et al. 2010

Clin Exp Pharma Physio

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1. Previous work indicates that agonists of ghrelin receptors can act within the spinal cord to stimulate autonomic outputs to the colorectum and to blood vessels. Because of the close relationship between colorectal and urinary bladder control, we have investigated whether ghrelin receptor agonists also stimulate spinal centres that influence the bladder. 2. The ghrelin receptor agonist capromorelin (10 mg/kg), injected intravenously in anaesthetized male rats, disrupted the ongoing cycle of micturition reflexes and caused phasic oscillations in pressure that averaged approximately 20 mmHg. Fluid output from the bladder was diminished. The effects of capromorelin were inhibited by hexamethonium (10 mg/kg bolus followed by 4 mg/kg per h infusion, i.v.) and were further reduced by atropine (5 mg/kg bolus followed by 2.5 mg/kg per h infusion, i.v.). Capromorelin (250 microg) injected directly into the spinal cord at the lumbosacral level also increased contractile activity of the bladder. However, capromorelin, up to 0.1 mmol/L, had no effect on the tension of isolated muscle strips from the bladder. Effects of intravenous capromorelin (10 mg/kg) on bladder pressure were still observed after the descending pathways in the spinal cord were disrupted at the thoracic level. 3. In situ hybridization studies revealed ghrelin receptor gene expression in neurons of the autonomic intermediolateral (IML) cell columns. Following a series of micturition reflexes elicited by infusion of saline into the bladder, the immediate early gene product c-Fos was observed in neurons of the lumbosacral IML and approximately 20% of these also expressed ghrelin receptor gene transcripts. 4. It is concluded that ghrelin receptors are expressed by lumbosacral autonomic preganglionic neurons of the micturition reflex pathways and that ghrelin receptor agonists stimulate these neurons.

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Section: Resultssupporting

confidence: 83%

Evidence for functional ghrelin receptors on parasympathetic preganglionic neurons of micturition control pathways in the rat

Ferens¹,

Yin²,

Ohashi-Doi³

et al. 2010

Clin Exp Pharma Physio

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“…A laminectomy was performed on the T13-L1 vertebrae exposing the L2 - S1 segments of the spinal cord. The origin of the L2 dorsal root is located in the caudal T12 vertebral section (Gelderd and Chopin 1977, Padmanabhan and Singh 1979). As a result, the caudal end of the T12 vertebral bone was removed in order to locate the L2 dorsal root.…”

Section: Methodsmentioning

confidence: 99%

“…Stimulation sites were positioned within rostrocaudal, mediolateral, and dorsoventral coordinates (or tracts) derived from the L2 dorsal root, middle blood vessel, and the surface of the spinal cord (Figure 2). The locations of the dorsal roots and vertebral spinal segments were observed under the surgical microscope and compared to published anatomical data (Gelderd and Chopin 1977, Padmanabhan and Singh 1979). The locations were similar in each rat and matched the published records.…”

Section: Methodsmentioning

confidence: 99%

A 3D map of the hindlimb motor representation in the lumbar spinal cord in Sprague Dawley rats

et al. 2016

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Objective Spinal cord injury (SCI) is a devastating neurological trauma with a prevalence of about 282,000 people living with an SCI in the United States in 2016. Advances in neuromodulatory devices hold promise for restoring function by incorporating the delivery of electrical current directly into the spinal cord grey matter via intraspinal microstimulation (ISMS). In such designs, detailed topographic maps of spinal cord outputs are needed to determine ISMS locations for eliciting hindlimb movements. The primary goal of the present study was to derive a topographic map of functional motor outputs in the lumbar spinal cord to hindlimb skeletal muscles as defined by ISMS in a rat model. Approach Experiments were carried out in nine healthy, adult, male, Sprague Dawley rats. After a laminectomy of the T13-L1 vertebrae and removal of the dura mater, a four-shank, 16-channel microelectrode array was inserted along a three-dimensional (200 µm) stimulation grid. Trains of three biphasic current pulses were used to determine evoked movements and EMG activity. Via fine wire electromyographic (EMG) electrodes, Stimulus-Triggered Averaging (StTA) was used on rectified EMG data to determine response latency. Main results Hindlimb movements were elicited at a median current intensity of 6 µA, and thresholds were significantly lower in ventrolateral sites. Movements typically consisted of whole leg, hip, knee, ankle, toe, and trunk movements. Hip movements dominated rostral to the T13 vertebral segment, knee movements were evoked at the T13-L1 vertebral junction, while ankle and digit movements were found near the rostral L1 vertebra. Whole leg movements spanned the entire rostrocaudal region explored, while trunk movements dominated medially. StTAs of EMG activity demonstrated a latency of ~4 ms. Significance The derived motor map provides insight into the parameters needed for future neuromodulatory devices.

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“…Brains were removed by careful dissection. Cord segments were defined by the corresponding vertebrae even though these are not exactly equivalent to the segments as defined by nerve roots (Padmanabhan & Singh, 1979). Cord segments were taken between thoracic vertebrae 6 and 9 and lumbar vertebrae 2 and 5.…”

Section: Tissue Preparationmentioning

confidence: 99%

Pathogenesis of Mouse Scrapie: Dynamics of Vacuolation in Brain and Spinal Cord After Intraperitoneal Infection

Cole

Kimberlin

1985

Neuropathology Appl Neurobio

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At the late clinical stage of scrapie in mice, the severity and distribution of vacuolation in the brain (the lesion profile) is largely determined by the strain of agent and the genotype of the mouse: under controlled conditions, lesion profiles can be used to distinguish between scrapie strains. This paper describes the sequential development of lesions in brain at much earlier times and includes a study of spinal cord. Mice (CW) were infected intraperitoneally with 139A scrapie. Grey matter vacuolation first occurred in thoracic cord, developing later in lumbar and cervical cords, and then in various brain regions in a caudal to rostral sequence. This pattern closely matches the sequential spread of infection from mid-thoracic cord to much of the CNS that was previously found in this scrapie model. Further studies of grey matter in spinal cord suggest that agent entered the mid-thoracic region via sympathetic fibres. Vacuolation in white matter mirrored the grey matter pattern within an area but always occurred later. The severity of grey matter vacuolation in the four areas of the CNS where it developed early, reached plateau levels before the clinical stage of scrapie, but the severity was still increasing at the clinical stage in areas where vacuolation had started late. Hence the severity of lesions in a particular area may sometimes be limited by the time available for them to develop before the host dies. It appears that the distribution of vacuolation in this particular scrapie model is initially influenced by that of the infectious agent and only later does it reflect the distribution of vacuolation target areas shown by the characteristic lesion profile.

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Observations on the topographical relations of spinal nerve roots in the rat

Cited by 22 publications

References 1 publication

Evidence for functional ghrelin receptors on parasympathetic preganglionic neurons of micturition control pathways in the rat

Evidence for functional ghrelin receptors on parasympathetic preganglionic neurons of micturition control pathways in the rat

A 3D map of the hindlimb motor representation in the lumbar spinal cord in Sprague Dawley rats

Pathogenesis of Mouse Scrapie: Dynamics of Vacuolation in Brain and Spinal Cord After Intraperitoneal Infection

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